Well, the price is very low so it's not a big issue but... I already knew this trick and i was looking to transform it into an effect. I hoped to find a fresh routine, something funny, even brilliant but... this is not the case. It's flat and uncharming, something that don't resolve the slightly boring soul of this trick. Even worse: the routine don't have an ending because the author continued with another routine (not showed in the doc). To me it's like a quick cut and paste of a very old and uninspiring material.
Is this an interesting trick? Yes
Is this the best way to learn it? I don't think so.